Lecture 5 - Hydration

Question 1

what is euhydration

Answer 1

normal state of body water

Question 2

what is hyperhydration

Answer 2

a sustained increased state in body water

Question 3

what is hypohydration

Answer 3

a sustained decreased state in body water

Question 4

what is dehydration

Answer 4

the process of losing body water, rather than a state of low body water

Question 5

how does the body gain water

Answer 5

metabolic water production

food

drink

Question 6

how does the body lose water

Answer 6

faecal

respiratory

urine

sweat

Question 7

what are the negatives to measuring pre exercise hydration with urine osmolarity

Answer 7

• accuracy needs first void sample
• expensive

Question 8

what are the negatives to measuring pre exercise hydration with urine specific gravity

Answer 8

accuracy needs first void sample

Question 9

what are the positives to measuring pre exercise hydration with urine specific gravity

Answer 9

relatively cheap and quick results

Question 10

what are the positives to measuring pre exercise hydration with urine colour

Answer 10

very cheap and quick results

good education tool

Question 11

what are the negaitves to measuring pre exercise hydration with urine colour

Answer 11

accuracy needs first void sample

affected by other dietary components

Question 13

what is the negaitve to measuring pre exercise hydration with serum osmolarity

Answer 13

expensive

Question 14

what is the positive to measuring pre exercise hydration with serum osmolarity

Answer 14

accuracy gold standard

Question 15

what are the guidelines to hydration in exercise

Answer 15

begin exercise euhydrated

slowly drink 5-7 ml/kg at least 4 hours prior to exercise

if urine still dark drink further 3-5 ml/kg 2 hours prior

Question 16

what does dehydration cause a decrease in

Answer 16

decrease in skill and mental performance

Question 17

what does dehydration open

Answer 17

opening of the blood brain barrier

Question 18

what does dehydration increase

Answer 18

increased perception of effort

Question 19

what is the equation to measure sweat loss used in practice

Answer 19

sweat loss (L) = Body mass loss (kg) + fluid intake (L) - urine produced (L)

Question 20

what is the equation to measure dehydration used in practice

Answer 20

dehydration = (body mass loss / initial body mass) *100

Question 21

in terms of hydration during training, do players know what they are doing

Answer 21

not really

Question 22

what are the possible effects of over hydration

Answer 22

• increase in body mass
• urination
• dilution of blood sodium
• possibly hyponatremia

Question 23

what is hyponatremia linked to

Answer 23

serum sodium concentration

Question 24

what are the symptoms related to hyponatremia

Answer 24

• fatigue
• lethargy
• brain aneurisms
• possible death

Question 25

what are the risk factors to hyponatremia

Answer 25

- exercise duration >4h - slow speeds - females - low body weight - excessive fluid intakes - non steroidal anti inflammatories - extreme environments

Question 26

the addition of sodium to drinks ingested during exercise cannot .....

Answer 26

cannot prevent the development of exercise associated hypoantraemia in athletes who drink to excess

Question 27

what are the ACSM drink guidelines

Answer 27

- try to limit dehydration to <1-2% loss in body mass - in hot environments this may not be feasible, in this case try to minimise dehydration - avoid gaining weight

Question 28

excessive water intakes are more common in what athletes

Answer 28

recreational athletes

Question 29

what electrolyte lost in sweat is

Answer 29

sodium

Question 30

how to calculate salt losses

Answer 30

sweat sodium concentrations (mmol/L) * sweat loss (L/h)

Question 31

sodium improves palatability, what does this increase

Answer 31

increasing palatability could increase fluid intake thereby delaying the onset of dehydration

Question 32

fluid intakes are greatest with what concentration of sodium

Answer 32

30 mmol/L NaCl solution

Question 33

sports drinks are usually what sodium concentration, anything above this people usually wont drink them

Answer 33

20-40 mmol/L

Question 34

exercise less than 24 hours apart requires a more ...

Answer 34

structured rehydration plan

Question 35

what type of volumes are best for rehydrating after exercise

Answer 35

smaller regular volumes

Question 36

what are the three R aims of recovery

Answer 36

- restore - rehydrate - repair

Question 37

what is meant by restore in recovery aim

Answer 37

muscle and liver glycogen levels to pre exercise

Question 38

what is meant by rehydrate in recovery aim

Answer 38

restore fluid and electrolyte balance

Question 39

what is meant by repair in recovery aim

Answer 39

muscle repair and regeneration

Question 40

study found what happens if you just replace body weight lost in rehydration post exercise

Answer 40

you wont get back up to euhydrated

Question 41

how many times body mass losses is required to become euhydrated post exercise

Answer 41

1.5 time body mass losses

Question 42

sodium is the major ion of the what fluid

Answer 42

extracellular fluid

Question 43

The addition of carbohydrate to rehydration drinks enhances fluid retention if the concentration of carbohydrate is .... and volume of fluid is ..... ingested are sufficiently high

Answer 43

(6-10%) .... (150% BM loss)

Question 44

what are best when used together not in isolation to support recovery

Answer 44

protein, carbohydrates and water

Question 45

why include sodium ? ?

Answer 45

- improves palatability - maintains extracellular volume - may attenuate the decline in blood sodium

Question 46

what are the ACSM carbohydrate guidelines

Answer 46

a carbohydrate intake of 1.5 g/kg during the first 30 min and again every 2 hours for 4 to 6 hours will be adequate to replace glycogen stores

Question 47

what are the ACSM rehydration guidelines

Answer 47

1.5 times body mass loss

Question 48

what are the ACSM protein recommendations

Answer 48

0.25-0.3 g/kg

Question 49

what is euhydrated in urine osmolarity measure

Answer 49

<700 mOsmol/kg

Question 50

what is euhydrated in urine specific gravity measure

Answer 50

<1.020 mg/cm3

Question 51

what is euhydrated in urine colour

Answer 51

<3 on the scale

Question 52

what is euhydrated in serum osmolarity measure

Answer 52

~285 mOsmol/kg

Question 53

when is beverage temperature important

Answer 53

when exercising in the heat

Question 54

exercise induced hypohydration leads to (what is the overall effect of this)

Answer 54

decreased plasma volume increased plasma osmolarity increased thirst decreased mood these have secondary impacts that leads to impaired endurance performance

Question 55

even without fluid ingestion how much plasma volume is restored and when

Answer 55

half of the loss in plasma volume is restored within 1 hour

Question 56

how can total estimated sweat loss be calculated

Answer 56

(pre exercise weight - post exercise weight) + fluid consumed during exercise - urine produced

Question 57

how to work out estimated sweat rate

Answer 57

total estimated sweat loss / exercise duration

Question 58

how to work out level of dehydration (%)

Answer 58

weight change / pre exercise weight x 100 weight change (pre exercise body mass - (post exercise body mass + urine)) x 100 / pre exercise weight

Question 59

what is the normal variation in body water

Answer 59

≤ 1% of body mass

Question 60

what is it reported of % lost of starting weight in marathon

Answer 60

9.8% starting weight lost

Question 61

what is one of the highest every sweat rates recorded

Answer 61

3.6L/hr

Question 62

what are the sweat potassium concentrations

Answer 62

~2-8 mmol/L

Question 63

what is the sweat sodium concentrations

Answer 63

20-80 mmol/L